Since an electron beam exposure apparatus includes mechanical portions, such as an electron optics body tube and a wafer stage, and hardware portions, such as a digital control section and an analog amplifier, various abnormalities are likely to occur in the system. Therefore, in order to expose a wafer accurately in the electron beam exposure apparatus, it is required to detect these abnormalities in the system certainly.
For example, an electron beam exposure apparatus disclosed by the Japanese Patent Application Laid-Open No. 1996-279450 includes: a buffer memory for temporarily storing exposure data stored in hard disk; two pattern generation sections for outputting shot data, which are divisions of the exposure data output from the buffer memory being split into shots; a first comparing section for comparing two shot data output from the two pattern generation sections respectively; two pattern correction sections for correcting and outputting the shot data output from the two pattern generation sections respectively; a second comparing section for comparing the two shot data output from the two pattern correction sections respectively; two exposure sections for performing exposure based on the shot data output from the two pattern correction sections respectively; and a third comparing section for comparing the pattern generated by the two exposure sections. Based on the comparison result by the first comparing section, the comparison result by the second comparing section and the comparison result by the third comparing section, the electron beam exposure apparatus detects an abnormality of the data, and specifies cause of the abnormality in the system.
However, the buffer memory of the electron beam exposure apparatus, which is disclosed by the Japanese Patent Application Laid-Open No. 1996-279450, is required to output normal exposure data. Therefore, in case that the buffer memory does not operate normally and there appears an abnormality in the exposure data output from the buffer memory, the electron beam exposure apparatus is neither capable of detecting the abnormality of the data, nor specifying the cause of the abnormality in the apparatus.